This invention relates to composite wastewater samplers.
In one type of composite wastewater sampler, samples are automatically periodically drawn from a wastewater pipe under the control of a computer and the samples are permitted to flow into a large container which accumulates the samples. The wastewater in the container is used to determine the content of flow over a period of time to learn of the amount of different solids and liquids in a wastewater system.
In one prior art wastewater sampler of this type, a peristaltic pump periodically draws samples directly from the pipe and flows it to a single container. A composite wastewater sampler of this type is sold under the designation model 2710FR Fiberglass Refridgerated Composite Wastewater Sampler by Isco, Inc., P.O. Box 82531, Lincoln, Nebr. 68501-2531, USA. This type of composite wastewater sampler has some disadvantages in that: (1) the nozzle which draw fluid from the pipe is easily clogged, and (2) if not carefully monitored by a human operator, the container may overflow.
Another prior art type of composite wastewater sampler includes a wastewater pipe which extends into a cabinet and has an outlet port opening into a flow-through-chamber which is larger than the waste-water pipe. Wastewater flows into the flow-through-chamber of a larger flow-bed area from which samples of wastewater are scooped up and permitted to flow into a container. After the wastewater flows through the flow-through-chamber, it is forced back into a return section of the pipe. A composite wastewater sampler of this type is sold under the designation model TC-2 Sampler by Sonford Samplers, a Division of Comelex Corporation, 905 North 5th Street, Minneapolis, Minn. 55401, USA.
This type of composite wastewater sampler has several disadvantages, such as: (1) it does not draw an accurate sample of the solids in the wastewater because the solids settle to a lower level before the scope receives them; (2) it is relatively complicated; and (3) it requires careful monitoring by human operators to be sure that containers gathering the composite sample do not overflow and are replaced timely.